Problems with integration contours and residues

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In summary, integration of contours and residues is a method used in complex analysis to evaluate integrals over closed curves in the complex plane. This technique involves breaking down the function into simpler components and using the Cauchy integral theorem and formula. Problems with this method can arise due to singularities, contour choice, or function complexity. To overcome these problems, we can use techniques like contour deformation or other integration methods. Integration contours and residues have real-world applications in engineering, physics, and other fields, but they also have limitations, such as only being applicable to closed curves and being time-consuming for certain functions.
  • #1
nullus 1er
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1. Hi there,

I have problems in finding the correct results for these integrals. I have to say I m not a great expert in residues...


2. Int[-inf;+inf;exp(-x^2)/(z-x)]

variable is x, constant is z

Int[-inf;0;exp(x)/(z-x)] with z<0


3. I think the 1st one gives 2i pi exp(-z^2) and the second one 2i pi exp(-z)+something
 
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  • #2
These are not simple integrals that can be done by residues. The yields an error function and the second an incomplete gamma function.
 

What is integration of contours and residues?

Integration of contours and residues is a technique used in complex analysis to evaluate integrals over closed curves in the complex plane. It involves breaking down a complex function into simpler components and using the Cauchy integral theorem and Cauchy integral formula to calculate the integral.

Why do problems with integration contours and residues arise?

Problems with integration contours and residues can arise due to various reasons, such as singularities or poles within the contour, the choice of contour, or the complexity of the function being integrated. These problems can make it challenging to accurately calculate the integral using this method.

How can we overcome problems with integration contours and residues?

To overcome problems with integration contours and residues, we can use techniques such as deformation of the contour, choosing a different contour, or using other integration methods such as the residue theorem. It may also be helpful to simplify the function being integrated or use numerical methods to approximate the integral.

What are some real-world applications of integration contours and residues?

Integration contours and residues have various applications in engineering, physics, and other fields. They are commonly used in signal processing, control systems, and electromagnetic theory to calculate integrals over complex curves. They are also used in quantum mechanics and statistical mechanics to evaluate path integrals.

What are some limitations of using integration contours and residues?

Integration contours and residues have some limitations, such as only being applicable to integrals over closed curves in the complex plane. They may also be challenging to use for functions with singularities or poles that are not easily identifiable. Additionally, it may be time-consuming to evaluate the integrals using this method compared to other integration techniques.

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